Child sexual abuse is recognized as a national problem which has reached epidemic proportions. Its impact can have devastating psychological and psychosocial effects on the victim's current and future functioning. School-based educational programs represent the most common approach to the prevention of child sexual abuse. Yet, such programs have recently come under sharp criticism for their over-reliance on anecdotal clinical information and the assumption that we already know which skills reduce children's vulnerability to sexual abuse. Obtaining more detailed and systematic information regarding what happens in abusive situations and which techniques abusers use to engage and maintain their victims has been suggested as a means of enhancing the foundation of child sexual abuse prevention programs. This proposal offers a means of addressing these issues with a previously neglected, high risk group: 12-17 year old females. The primary goal of this series of studies is to create an empirical data base reflecting patterns of behavior that child perpetrators engage in, leading up to, during, and following sexually abusive acts. Information will be obtained from victims, incarcerated offenders, and non- incarcerated offenders regarding the modus operandi of intra- and extra- familial offenders. This investigation will be divided into two phases. Phase 1 will complete the development of a set of instruments intended to measure modus operandi of intra- and extra-familial victims and offenders. Phase 2 will utilize multiple data collection sites (geographically distributed around the continental U.S.) to obtain data from intra- and extra- familial victims and perpetrators regarding offenders' child sexual abuse modus operandi. Results will also offer insights regarding the extent to which offenders under-report their use of threats and coercion in the commission of their sexual offenses. Findings will have implications for: the evaluation of existing prevention programs; the development of new programs; and victim/perpetrator assessment and treatment. Two major prevention programs have also agreed to review study results for integration into their curricula and to assist in the dissemination of findings.